const moveDecorator:ClassDecorator = (target:Function) => {
    target.prototype.getPosition = ():{x:number, y:number} => {
        return {x:100,y:200}
    }
}

const musicDecorator:ClassDecorator = (target:Function) =>{
    target.prototype.playMusic = ():void => {
        console.log("播放音乐");
    }
}

@moveDecorator
@musicDecorator
class Tank{}
const t = new Tank();
console.log((<any>t).getPosition());
(<any>t).playMusic();